Room mirrors and door mirrors are known as vehicular parts for checking a vehicle surrounding area. In addition, there is known a device that displays an image of a blind spot for a driver, picked up by a camera, on a monitor in a vehicle as an image of a vehicle surrounding area.
To cause such a device to display an image of a vehicle surrounding area, a driver has to do a switch operation when feeling the necessity. The driver feels such a switch operation troublesome.
Patent literature 1 discloses a technology which automatically displays an image of a vehicle surrounding area.                Patent Literature 1: Unexamined Japanese Patent Application KOKAI Publication No. 2005-51403        